Ceramic tile



Sept. 22, 1959 R. w. EMMERLING CERAMIC TILE Filed Oct. 4. 1957 T, Wm M m.

United States Patent CERAMIC TILE Ralph- W1 Emmerling, (Canton, Ohio, assign'or to United StatesCeramic 'I-iIGCOmpany, Northeast Canton, Ohio,

a corporation of? Delaware:

t Application October 4,1957, SerialNo. 688,262

Claims. (Cl; ll-18) The present invention. relates to. floor, and wall. tiles and more particularly to a method of fabricating wall and floor tiles. andqto a tile construction. resulting therefrom which permits variation. of. tile dimensions to be main.- tained within; close tolerances and insures accurate and uniform spacing between the tiles in which to deposit an appropriate cementitious material.

In laying tile to form a floor or wall, a coating of cementitious material. is. first. spreadover. the surface to which the tiles are. to be cemented and thereafter the tiles. are laid. in generally perpendicular rows. and columns with a narrow spacing being provided between each tile. After the cementitious; material has set, a. further cementitious. material such as grouting compound. is applied to the spaces. between the individual tiles to complete: the tile setting operation. Considerable difiiculty arises in tile setting in consequence of the variations in dimensions of the. various. tiles, which result from the present method. of manufacture of the tiles. In fabricate ing, tiles. in. accordance with. prior art techniques, accurate molds. are employed whi'chhave internal. dimensions greator than. the final desired dimensions of. the block. The material for making the tilev isapplied to these. molds and due to shrinkage ofthematerial, the final size. of the tiles. is less than the internal. dimensions. of. the mold. The difiiculties. expeiienced in laying,tilesfabricatedin accordance with the prior art techniques arise from the fact that. shrinkage of the tile material during firing may be as much as. 3% and. may notbe uniform. ina single, tile or between tiles- The results. ofthe non-uniformity of shrinkage of the material in a single tile. may produce a tile having. a keystone shape while non-uniformity of shrinkage. ofv the material as between tiles produces tiles of different sizes. Obviously, both of these eifects hamper a tile setter since the tile havinga keystone shape will throw off the entire line of tile and tiles of different sizes making. it difficult for the tile setter to align the various rows and columns of the tiled surface.

In an effort to overcome the difficulties arising from the variations of size of tiles, tiles ofa given dimension such as 4%" by 4%" are soldin different sizes such as A, B and C, and Federal specification SS-T-308 permits variations of in each size. The tile setter must be careful to utilize the various sizes of tiles so that the rows and columns will come. out evenly. Further diificulties experienced as a result of variations of sizes of tiles. arise when a damaged tile must be replacedin a tiled surface. Here again a tile setter must select a particular tile within the proper A, B or C size so that it will fit in the space left by removal of the damaged tile.

The variations intile sizes and in shapes of the tiles resulting fromnon-uniform shrinking of the material during fabrication of the tiles often result in non-uniform grouting lines between the tiles which detracts from the appearance of the tiles. These size variations also cause serious inventory problems for the tile contractor, since it is necessary to maintain an inventory of the various tile colors and finishes in each of the various sizes.

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The appearance of. afinished tile; surface. depends al.- most as much. upon uniform, grouting as upon the tile itself and various efforts, have been. made in the, prior art to insure grout lines of uniformwidth. One effort to secure uniform grout, lines involves molding lugs on the edgesof the tile which abut. the adjacent tile. While these lugs will insure uniform. spacing between. these adjacent tiles, they do not in any way, allaviatethe difficulties resulting from non-uniform. tile size. and the molded lugs introduce new difiiculties of their own. as pointed out later.

It is often found in tiled. walls and floor structures utilizing the prior arttiles, that, the grouting compound does not hold very well to the sides of the tile and after extended periods.- of. use, the grout becomes loose and detaches itself from the wall. This defect may arise from several factors. One of these factors is that during the fabrication of, the tile some of the glaze adheres to the edge of the tile and the grouting compound will not adhere to the glaze. This. condition is aggravated in the case of lugged' tile. Another factor contributing to loosening of the grout is shifti'ngof the wall which results in cracking, and loosening of the groutwhich may fall out leaving an unsightly crack.

It is an object of the present invention to provide an edge construction for tiles which permits the variations of dimensions of the tiles to beheld within very close tolerances and which assures, uniform spacing between the tiles, and which provides a positive locking arrangement between the tiles on. the one hand and the tile grouting compound on the. other.

It is another object of the present invention to pro vide ceramic wall and floor tiles which have their edges ground to exact size to provide accurate spacing therebetween.

It is another object of the present invention to provide a method of fabricating glazed tiles which permits the size variations of the tiles to be held within such. close tolerances that only a single tile size need be inventoried and which assures that no glazing material will appear on the edges of the finished product.

In accordance with the present invention a ceramic tile is fabricated by applying the appropriate materials to a mold" and after firing, grinding the side walls of the tile to a predetermined standard. size. The initial tile as it comes from the mold is larger than. the final tile so that sufficient grinding may be employed to remove whatever glaze may have adhered to the edges and further to correct any keystone effect produced during shrinkage of the tile material. Since the tile is ground to size after molding, the effects of shrinkage during firing are less important. The side edge is ground on a bevel such that the dimensions of the top face of the tile are less than the dimensions of the bottom face.

A plurality of spaced undercuts are molded into each edge of the tile so that the portions subsisting between the undercuts constitute lugs which are intended to mate with corresponding lugs on adjacent tiles to provide appropriate spacing between adjacent tiles in a tiled surface. The lugs in actuality constitute the portions of the edges which are not undercut and therefore are ground to the desired size at the same time as the other portions of the edges are ground. As a finalstep in the fabrication of the tile, the feather edges formed by the grinding operation may be removed and the lugs are provided with a short vertical surface subsisting, at the bottom surface of the tile, the vertical dimension of the surface being of approximately a sixteenth of an inch or more or less as determined by the design and strength considerations.

It can be seen from above that the method of fabrication' and the edge construction resulting therefrom insures a tile of a uniform size, the tolerances of which may be maintained below 0.005 and as low as 0.002" for each tile and therefore only a single size tile need be inventoried or supplied to the tile setters. Upon laying a tile wall or floor each tile is laid such that the bottom edge of the uniformly tapered portions of the edges contact corresponding portions of the edges adjacent tiles and the uniform spacing is automatically effected. Upon applying a grouting compound between the spaced tiles, the compound flows down between the tiles and into the undercut portions to effect a locking arrangement between the tiles and the grouting compound. As a result of the grouting compound flowing into the undercut portions of the tiles substantially no diffiiculty is experienced with the material breaking loose from the wall and falling out since the undercut portions provide a positive engagement between the tile and the grout. Further, the difliculties resulting from the glaze on the edge of the tile have been eliminated as a result of the grinding step and therefore loosening of grout due to the presence of the glazed material on the side edges is eliminated.

It is, therefore, another object of the present invention to provide wall and floor tiles having outwardly sloping and ground edges in order to provide a uniform spacing between the tiles when assembled into a wall or floor.

It is still another object of the present invention to provide a wall or floor tile wherein the edges of the tile are ground to size and at the same time provided with an outward slope from the top of the bottom of the tile so as to provide mating outstanding portions which insure uniform spacing between the tiles.

It is another object of the present invention to grind ceramic wall and floor tiles to exact size and in the process of the grinding operation to provide an edge structure which insures an adequate and uniform spacing between adjacent tiles when assembled in a structure and further insures that there is no glaze on the edges of the tile.

It is another object of the present invention to provide a ceramic wall and floor tile having spaced undercut portions in its edges in order to provide a locking engagement between the grouting compound and the tiles.

It is another object of the present invention to provide a method of fabricating ceramic wall and floor tiles which permits the production of tiles of uniform size within very close tolerances.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a perspective view of a tile of the present invention;

Figure 2 is a top view of a tile fabricated in accordance with the present invention;

Figure 3 is a side elevational view of the tile of the present invention;

Figure 4 is a front view of a tiled structure employing the tiles of the present invention;

Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4;

Figure 6 is a cross-sectional view taken along line 6-6 of Figure 4; and

Figure 7 is an enlarged partial view of a side wall of a tile employing rounded ground surfaces.

Referring specifically to Figures 1, 2 and 3 of the drawing, the tile fabricated in accordance with the present invention comprises a top surface 1, a bottom surface 2 and four edges 3, 4, 5 and 6. Each of the edges tapers outwardly from the top 1 to the bottom 2 so that the bottom 2 has larger peripheral dimensions than the top 1. The edges 3, 4, 5 and 6, and reference is made to the edge 4 for purposes of illustration, are provided with a plurality of uniformly spaced surfaces 7 which extend over approximately the lower half of the edges and have a slope which is directed oppositely to the slope of the edge 4. Thus, the surfaces 7 have a slope or inclination which is directed inwardly from the center of the edge to the bottom surface 2-. In consequence of this configuration, the entire upper half of the edge 4 has a uniform outwardly sloping portion 8 and in one specific embodiment of the invention, as illustrated in the drawings, two lower half portions 9 which are coplanar with the upper half surfaces 8. The wall surfaces 7 between the outstanding surfaces or portions 9 form undercuts such that the portions 9 form lugs or projections on the edges 3, 4, 5 and 6 of the tile of the present invention. The lower ends of the portions 9 may terminate in a short vertical wall 10 which provides a flat abutting surface between tiles when the tiles are laid to form a tile surface. The bottom surface 2 of the tiles may be provided with a plurality of parallel ribs 11 which strengthen the bond between the tile and the cementitious material in which it is set.

As previously indicated, the object of the present invention is to provide a tile as illustrated in Figures 1 through 3 in which the variations and dimensions of the tile are held within very close tolerances and in which any glaze which might have adhered to the edges is removed.

In accordance with the present invention of fabricating the tiles 1, the ceramic or other material from which the tile is molded, is applied to a mold having an internal configuration conforming to the external configuration of the tile illustrated in Figure 1 but somewhat larger in size, so that even after shrinkage the tile is larger than desired. After the molding operation, the four edges of the tile are ground and grinding is continued until the tile is of a precise dimension.

Ordinarily a single pass between the grinding wheels is sufficient to finish the opposed edges of a tile, but this single pass does leave a sharp feather edge at the juncture of the surface 9 and the bottom surface of the tile. Since the tiles are brittle, this feather edge may be chipped in handling. This difficulty may be corrected by passing the tile again between two parallel grinding wheels to form short, vertical surfaces 10. The formation of these surfaces is entirely optional, although it is frequently preferred.

During the grinding operation all glaze that may have run onto the side wall is removed, the tiles are brought to a precise dimension and any keystoning effect that may have resulted from non-uniform shrinkage of the tile is eliminated since the wheels for grinding the various side walls of the tile are maintained in position within extremely close tolerances. Thus, in a single operation, precise dimensioning of the tile is effected and glaze is simultaneously removed from the side walls. Further, in consequence of the molding of the undercut 7 in the side walls, the portions 9 between thme undercuts, provide lugs which are adapted to engage with corresponding lugs on adjacent tiles when the tiles are laid to effect uniform spacing between the tiles.

As pointed out above, the undercuts 7 are molded into the tile when it is formed and before firing, and because of their location, these undercuts are protected from glaze applied to the top surface 1. The sloping surfaces 8 and 9 on each of the edges 3, 4 and 5 are somewhat larger than the finished tile and after the tile has been fired, it can be passed between two grinding wheels which are set at the proper angle and spaced the proper distance apart so that opposite edges of the tile may be finished simultaneously to precise dimensions. That is to say, the surfaces 8 and 9 of the edges 3 and 5 would be finished simultaneously by passing the tile between two accurately positioned grinding wheels and the tile can then be turned and the edges 4 and 6 passed between the two grinding wheels, thus finishing the tile to precise dimensions and also insuring a smooth and accurate a manac stoodthat the circular'eilge of thegrinding wheel'may be used giving a concave edge to the tile as shown '11]. .Figure 7.

Proceeding now to setting or a wall or floor employing the tiles of the present inventiomlre'fer'ence isrnade to Figure '4 of the accompanying "drawings wherein 1s illustrated a surface composed of a plurality of tiles fabricated in accordance with the present invention, the spacing between the tiles being exaggerated in this figure to more clearly illustrate the invention. Upon the tiles being set in cement or other suitable bonding material, a first tile is laid and a subsequent tile is placed adjacent thereto with adjacent portions 9 being aligned with one another so that the adjacent undercut portions 7 are also aligned one with the other. Inasmuch as the edges 3, 4, 5 and 6 of each tile are tapered outwardly from the top surface 1 to the bottom surface 2, and reference is now made specifically to Figure 6, the edges 10 of the members 9 abut one another and form a V between the tiles so that the upper portion of the edges stand off one from another by a distance determined by the taper or angle of the edges. Thus, the spacing between the upper edges may be readily controlled and be made to conform to any spacing desired by merely selecting an appropriate taper for the edges.

When grouting compound is applied between the tiles, the V-shaped portions between the members 9 are completely filled as are the spaces between the portions 7 as illustrated in Figure 5. As can be readily seen by a reference to Figure 5, the grouting compound passes through the narrowest space in this segment and into the undercut region between the reversely sloped segments 7. Since the grouting compound which is generally designated by the reference numeral 12 extends into this undercut region, it is positively locked into place and cannot be dislodged unless there is a complete disintegration of the material.

Referring specifically to Figure 7 of the accompanying drawings, there is illustrated a tile having an edge 13 which tapers outwardly from the top surface 14 to a bottom surface 15 but wherein the edge is ground on the arc of a circle. The radius of curvature of the edges 13 is such as to provide a substantially straight contact surface which in no way interferes with the desired functioning of the device. The edges 13 are provided with undercut portions 16 as in Figures 1 to 6.

The embodiment of the invention illustrated in Figure 7 is intended to show that the specific shape of the various ground edge surfaces of the tile of the present invention may take various forms, it not being intended to limit the invention to a specific straight edge construction as illustrated in Figures 1 to 6 of the accompanying drawings.

The extent of the undercut sections of the edges is determined by many factors and may accordingly be varied considerably. Thus, although the undercut sections are illustrated as extending to the approximate vertical centers of the edges, the invention is not limited to such a construction. The undercut sections may extend to any portion of the edges but preferably extend to a position at least one-third of the distance from the bottom Wall. The multiple point of contact between adjacent tiles provided by the undercuts is preferable to a solid line of contact since better alignment may be effected. It is well known that a multiple point contact is more likely to provide proper seating between two objects than a solid line of contact with its many imperfections, and thus the undercut segments serve not only to positively grip the grouting compound but also to insure better contact between adjacent tiles.

6 n was be readil seen from the :above that t-he construction of-the tile-ofthe present invention "readily lends =iself to fabrication by grinding as the "final shaping step at the fabrication operation. The grinding :implements for -grinding the Mile to its "exact size are 'set at such an ang'le with "respect to j the tile that the "desired t-aper is provided on the side walls 3, 4, '5 'andb. A see- -0ntl *rapid grinding operation may then be employed --to remove the sharp edge of -fh'e *lower end of the lug portions of the side walls. For reasons of economy, the undercuts would always be molded in the tile but it is apparent that they could be ground.

The tiles of the invention are illustrated as being square but it is not intended to direct the invention to a specific shape since the side wall construction of the invention is applicable to all shapes of aligned tiles. Further, the invention is not limited to wall or floor tiles since it is equally applicable to multiple block constructions employing mortar and other related building elements.

At the present time, commercial tiles cannot be held to closer tolerances than 0.015" and this can be done only by selection of finished tile. It is impossible to hold the tiles this close by any commercial molding method. According to the present invention, the tile can be held to tolerances of 0.005" which will result not only in surfaces of neat and uniform appearance, but will greatly simplify inventory problems and replacement of broken tile.

While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the general arrangement and of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

WhatI claim is:

1. A multiple block construction including a plurality of blocks having first and second opposed surfaces and a plurality of edges interconnecting said first and second surfaces, said edges being inclined outwardly from said first surface toward said second surface and including a plurality of spaced portions having surfaces inclined outwardly from said second surface toward said first surface for a portion of said edges, said blocks being arranged in edge abutting relationship with respect to one another so that said plurality of spaced portions of adjacent edges of adjacent blocks are aligned with one another.

2. A multiple block construction as defined in claim 1 in which the edge surfaces intermediate said spaced portions include a small flat abutting said second surface.

3. A ceramic tile comprising first and second opposed surfaces, at least four edge surfaces interconnecting said first and second surfaces, said edge surfaces being angularly disposed to each other and inclining outwardly from said first surface toward said second surface, each of said edge surfaces including a plurality of spaced undercut portions extending from said second surface toward said first surface and terminating between said first surface and said second surface, said spaced portions being positioned and dimensioned along the length of each of said edge surfaces whereby the outer tips of said edge surfaces intermediate said spaced portions may be aligned in contact with similar tips on adjacent tiles.

4. A glazed ceramic tile comprising a first glazed upper surface and a second opposed unglazed lower surface, four glaze-free edge surfaces interconnecting said first and second surfaces, said four edge surfaces being ground precisely perpendicular to each other and inclining outwardly from said first surface toward said second surface, each of said four edge surfaces including a plurality of spaced undercut portions extending upwardly and outwardly from said second surface toward said first glazed surface and terminating between said first surface and said second surface, said spaced portions being symmetrically positioned and dimensioned along the length of each of said four edge surfaces whereby the outer tips of any one of said four edge surfaces intermediate said spaced portions may be aligned in contact with similar tips on any one edge surface of an adjacent tile.

5. A glazed ceramic tile according to claim 4 wherein said spaced portions terminate approximately equidistant from said first and second surfaces.

References Cited in the file of this patent UNITED STATES PATENTS Morse Dec. 13, 1870 Marvick Nov. 10, 1908 Triol Aug. 19, 1924 Whitacre Dec. 14, 1937 Heyden Dec. 14, 1945 Le Clercq Jan. 31, 1956 

